Saturday, March 5, 2011

Dude2's Straw Bale Garden

Dude1 got the jump on me by about a week on the straw bale setup, but I finally got it together yesterday to get my garden started as well. I've done some gardening before and really enjoyed it, so I was a bit dismayed at the timing of buying my new farm -- I got it in the fall, and because of other work I had to do I wasn't able to prepare a garden spot. I decided that it would be best to make a straw bale garden the first year, then use all that wonderful compost to prep the dirt-based plot that I'll be using during subsequent years.

Last year I did a square foot garden that I was quite pleased with despite its relatively small size. We grew hot peppers (habanero, scotch bonnet, fatalii, jalapeno, etc.), tomatoes, salad veggies, potatoes, okra, and a ton of herbs and miscellaneous other experiments, all mixed together in the plot. We had very little difficulty with pests, but weeds were a constant struggle. Theoretically, straw bale gardens will handle the weed problem nicely.

I like to garden in a big way, so I'm starting with 90 bales this year. Part of the reason is that my 10x30 plot felt too small last year, and the other part is that I love doing experiments. When I started researching straw bale gardens, there was a real shortage of information about how to use this approach while sticking to organic methods, so I decided that I would take this opportunity to do a little research myself and maybe push that part of the system a little further along. I'll post my notes on what works and what doesn't as the season progresses, so that hopefully we can start to get some real data on this quick and easy gardening method.

Dude1 wrote a great post about his straw bale garden that covered the basic ideas, so I won't repeat that here. Instead I'll try to describe the experiments I'm doing and why I'm doing them.

Experiment 1: Nitrogen Source

If you peruse the web looking for information about organic straw bales, the number one piece of advice you'll find is to use blood meal as a source for the nitrogen that the microbes need to start the composting process. This is fine, except that blood and bone meal are getting to be harder to find in decent quantities because of bovine spongiform encephalitis (BSE, or mad cow disease). The primary place to buy this stuff used to be at feed stores, but because of the threat of BSE, they are no longer permitted to sell it. You can still buy it, but it's far more expensive now because it comes from garden centers. In order to apply it at the full rate to a garden of this size, it would end up costing about $400, which is a little tough to chew, considering a dirt garden is nearly free.

I decided I would still use it, but only on a section of the garden. I bought 8 lbs of blood meal and 4 lbs of bone meal and mixed them together:

Then I applied it to my bales at a rate of about a cup per bale:

Here you can see the bale after the fertilizer has been applied:

I will do three more applications like this, spaced out by a couple of days to allow the previous application to spread into the bale, then I'll leave them to compost. I'm lucky enough to be doing this during the rainiest part of the year, so I don't need to do much bale watering out here. It rained about two inches here last night! Without the rain, though, you'd need to keep on top of it to make sure the bales don't dry out.

For other nitrogen sources, I'm looking at alfalfa meal, cottonseed meal, and straight hay (no added nitrogen). This page has information about the properties of the seed meals, but I'll summarize it by saying that alfalfa meal is a somewhat low grade nitrogen source (about 1/4 that of blood meal) that decomposes at a decent pace, while cottonseed meal has double the nitrogen but is much slower to decompose. I'm figuring I'll apply them at rates so that the same total amount of nitrogen is applied to all bales (so I'll use 4 cups of alfalfa meal and 2 cups of cottonseed meal per bale, in four applications).

I'm hoping that the alfalfa meal and cottonseed meal work out, because the money side of things is much better with those sources of nitrogen. For a smaller garden, this is not so much of an issue (it'll cost you about $25 probably), but every penny counts, right?

Experiment Two: Straw Orientation

If you look at my garden picture, you can kind of see that some bales are set with the straw in a vertical orientation,

and others are set in a horizontal orientation.

I've seen good recommendations for both out on the 'net, so I thought I'd try them both simultaneously under similar conditions and see which ones are good for what. I'm going to try to make sure I have each of the different types of nitrogen represented equally on both orientations as well, though when you start subdividing the garden into this many little sections local variation can become pretty important. Hopefully it'll provide some useful information about water use and root development though.

Experiement Three: AACT

AACT: Actively Aerated Compost Tea. If you read the book Teaming With Microbes (an excellent and highly recommended book), it's easy to come away with the idea that AACT can save the world. It's a compost tea made by taking a small amount of compost, adding a bit of simple sugar or starch as microbe food, and mixing it with a large amount of water that has air bubbling though it. The idea is that you can build up the soil community (ultimately the source of all fertility) by creating a massive inoculation of "good guy" microbes. The process is simple, and I'll be using it on some of my bales to see how it effects the compost process. Many sources also recommend spraying it onto the leaves of plants as a preventative measure for halting bacterial diseases and for feeding the plants (plants take in many nutrients through their leaves, not just sunshine). I'll try both of these approaches and try to report on any differences I see as a result.

Experiment Four: Root Crops

Most of the sources about straw bale gardening say that root crops won't make it in the bales. There may be a body of evidence to support that, but I can't find it. Sometimes a piece of information like that is repeated so often that it becomes wisdom, when the original basis was just one or two failed attempts. I decided that I would try a few root crops in my bales using a couple of different planting tricks to see what I could find out about this. I'm particularly interested in potatoes, because they are often grown by hilling loose straw around established plants. Perhaps I can apply a similar technique in the straw bales? Only one way to find out.

Experiment Five: Dirt

There seem to be two schools of thought on the issue of dirt and straw bales: add dirt, and don't add dirt. For direct sowing of seeds, you definitely need at least a little dirt to rest the seed on and to keep it moist for germination. I've seen three different approaches to this: a dirt trench on top of the bale, little pockets of dirt cut into the bale where the seeds are, and simply sprinkling a layer of dirt on top of the bale. I'll try each, and no dirt at all, and let you know what I can find out. I have a feeling that the trench method might be really good for the root crops, so that's a combination I'll be sure to try.

I'd love to make this blog into a one stop shop for straw bale info, so if you have experiences or good references on the topic please feel free to share! I'd also welcome suggestions for other experiments that need doing, or better ways to do the ones I'm planning.

I'm hoping that after this season, the straw bale gardening community will have at least some more starting points for getting organic vegetable patches going. One of the things we'd really like to see is an explosion of home and neighborhood gardens, and if this method works out it'll be a great way for a lot of people to get started.

3 comments:

@SBC -- not a problem at all. In fact, I want them to grow as much microflora as possible, to speed the decay. As long as the composting process is aerobic, it will result in a beneficial environment for the plants.